1. Field of the Invention
The present disclosure relates to computer-aided design and manufacturing, and more particularly to systems, methods, apparatuses, and computer-readable storage media for designing and manufacturing prosthetic dental items, such as teeth or one or more portions thereof.
2. Description of Related Art
Conventionally, a dental restoration procedure that includes creating a prosthetic dental item has been a laborious and time-consuming “trial and error” process. A dentist begins the dental restoration procedure by removing plaque from a patient's teeth in preparation for creating a profile of the patient's teeth and gums. The dentist can create a dental mold of the patient's teeth and gums by capturing a physical impression of the patient's teeth and gums using a molding material. The dental mold is forwarded to a dental laboratory where a physical, three-dimensional model of the patient's teeth and gums is created.
At the dental laboratory, a technician pours plaster into the mold. Once the plaster dries and is removed from the mold, the molded plaster is used as a physical, three-dimensional model of the patient's teeth and gums. If a dental restoration procedure includes replacing a missing tooth with a prosthetic tooth, the technician can build a wax model of the missing tooth using the plaster model of the patient's teeth and gums. The wax model can be used to cast a metal framework to which porcelain will be adhered. The technician adjusts coloring of the porcelain and fires the porcelain and the metal framework in a furnace to bake the porcelain onto the metal framework to create the prosthetic tooth. The technician can add several additional layers of porcelain to the prosthetic tooth to simulate natural color properties (e.g., hue, saturation, and chrominance) of the patient's missing tooth. Once the prosthetic tooth is finished, the technician returns the prosthetic tooth to a dentist, who examines it, and occasionally return it to the laboratory for re-working if problems with the color properties or dimensions of the prosthetic tooth are discovered.
More recently, computer-aided design (CAD) and computer-aided manufacturing (CAM) technologies have been used to create prosthetic dental items. CAD/CAM technologies can be employed to produce prosthetic dental items that fit into a patient's mouth more precisely compared to prosthetic dental items built using conventional techniques. In addition, prosthetic dental items built using CAD/CAM technologies can be produced more quickly than with conventional techniques. For example, Sirona Dental Systems produces a Cerec® system that can be used in a dental professional's office to perform a dental restoration procedure during a single office visit.
When current CAD/CAM technologies are used, a digital representation of a patient's teeth and gums typically is created at the outset of a dental restoration procedure. That is, data representing a three-dimensional surface of a patient's teeth and gums are acquired and stored in a digital data format. There are several advantages to using such digital representations of patients' teeth and gums. For example, immediately after the digital representation of the patient's teeth and gums is created, it can be shared by a dental clinician and a designer of a prosthetic tooth, which can expedite a dental restoration process. In addition, the digital representation of the patient's teeth and gums can be extremely precise.
Aesthetic properties of prosthetic dental items can be extremely important. For example, to make a prosthetic tooth look real or natural in a patient's mouth, color properties of the prosthetic tooth can be matched with color properties of teeth surrounding an area where the prosthetic tooth is to be installed in the patient's mouth. With a conventional manufacturing process, a dental technician akin to an artisan can color and shade the prosthetic tooth using the technician's training, experience, and imagination. An operator of a dental CAD/CAM system may or may not have the same training and experience as a conventional dental technician. Accordingly, it can be useful for a dental CAD/CAM system to assist operators to create prosthetic dental items having aesthetic properties that are comparable or superior to aesthetic properties of dental items created by skilled dental technicians using conventional techniques.
Current dental CAD/CAM systems can employ a ceramic block that is milled by a milling machine to produce a prosthetic dental item. A dentist can select a monochromatic block based upon desired aesthetic properties, e.g., color shading, of the prosthetic dental item to be produced. To determine desired color properties, for example, the dentist can use a template or a computerized shade system, such as the VITA Linearguide 3D-Master® from Vident. Generally, such computerized shade systems do not consider certain aesthetic properties, such as translucency, for example. In addition, a single, monochromatic block cannot always represent certain aesthetic properties of natural teeth, such as complex combinations of hue, saturation, and chrominance of a tooth in a region where the tooth transitions from a gingival surface to an occlusal surface, for example. That is, a single, monochromatic block or polychromatic block often cannot represent gradual transitions in shades of colors that are present in natural teeth.
For example, FIG. 2 shows a simulated image or rendering of a plurality of prosthetic teeth 202-212. Each of the plurality of prosthetic teeth 202-212 includes one or more gradual transitions in shades of colors that can be present in natural teeth.
In addition to having natural aesthetic properties, e.g., coloring, a prosthetic dental item ideally should be mechanically stable to prevent it from breaking prematurely when used by a patient. With conventional manufacturing of prosthetic dental items, a skilled dental technician can produce a prosthetic dental item having a high degree of mechanical stability by applying the dental technician's training and experience. As mentioned, operators of current dental CAD/CAM systems may not always receive the same training as convention dental technicians. In addition, current dental CAD/CAM operators may not have adequate expertise for producing prosthetic dental items having very high degrees of mechanical stability. Accordingly, it is can be useful for a dental CAD/CAM system to assist operators to create prosthetic dental items having mechanical properties that are comparable or superior to mechanical properties of dental items created by skilled dental technicians using conventional techniques.